The invention relates to meat processing and, more particularly, to an apparatus and method for improving the quality of meats which have been exposed to ammonia.
Meat products are inevitably exposed to microbes as the products are processed or handled. Microbes are part of the natural decay process of organic material and are commonly deposited on a meat product by contact between the meat product and contaminated equipment or other material. Microbes may also be airborne. Although some microbes may be relatively benign, others contribute to spoilage and some can cause serious illness. Lactic acid producing bacteria are examples of benign microbes, while some strains of E. Coli, Salmonella, Listeria, and Staph bacteria are examples of pathogenic microbes which can cause serious illness when ingested by humans.
Even with careful processing practices, meat products may be exposed to pathogenic microbes during processing or initial handling. However, the risk of illness from dangerous microbes which may be present in meat products is reduced by careful handling and cooking. In larger cuts of meat for example, dangerous microbes may only be present on the surface of the meat and are readily killed in the cooking process.
Comminuted and mixed meat products, including ground beef, require more thorough cooking in order to kill dangerous microbes which may be present in the material. The reason for this is that dangerous microbes residing at the surface of a larger piece of meat may be distributed throughout the final comminuted product as the large piece is ground or otherwise cut into smaller pieces and mixed with other pieces. Thorough cooking is required in order to kill microbes residing in the center of a piece of comminuted meat product.
Even though the risk from microbes residing in meat products is reduced by proper cooking, it is desirable to control the growth of pathogenic microbes and reduce pathogenic microbe content in meat products. Various methods have been developed for improving the quality of meat products by reducing or controlling pathogenic microbe content in the products. U.S. Pat. No. 5,871,795, to the inventor of the present invention, discloses a method using ammonia to modify the pH of a meat product. The ammonia treatment disclosed in U.S. Pat. No. 5,871,795 has been shown to decrease pathogenic microbe content in meat products, and to inhibit pathogenic microbe growth after treatment.
While the ammoniated (ammonia treated) meat products do exhibit decreased pathogenic microbe content, excessive ammonia exposure may have adverse effects on the product. For example, portions of the meat product being treated may be overexposed to ammonia while other portions of the meat product may be exposed to very little or none of the ammonia. The overexposed portions may absorb sufficient ammonia to affect the taste of the meat product and to produce a residual ammonia odor. Underexposed portions of the meat product may not exhibit the desired pathogenic microbe inhibiting effect.
It is an object of the invention to provide an apparatus and method for improving the quality of ammoniated meat products. More particularly, it is an object of the invention to provide an apparatus and method for ensuring a more even pH increase throughout an ammoniated, comminuted meat product.
The method according to the invention includes exposing at least a portion of a quantity of comminuted meat to ammonia. After exposing at least a portion of the comminuted meat to ammonia, the meat is further comminuted. Further comminuting the meat after ammonia exposure produces a meat product having much more even ammonia distribution. This more even distribution eliminates residual ammonia odor and produces a consistently better tasting comminuted meat product. Also, it is believed that the evenly distributed ammonia produces a more consistent microbe inhibiting effect throughout the volume of the further comminuted meat product.
Meat or meat products which may be treated according to the invention include beef, pork, lamb, and other red meats. Also, for purposes of this disclosure and the following claims the meat or meat product may comprise or include poultry or sea foods. The invention is not limited to any particular fat content in the meat product being treated. However, fat content may affect the amount of ammonia which may be added to the original comminuted meat product. Also, the meat product being treated may include various additives or fillers which are added either before or after the ammonia exposure.
As used in this disclosure and the following claims, a xe2x80x9ccomminutedxe2x80x9d material comprises generally a material which has been cut into relatively smaller pieces from one or more relatively larger pieces. The meat product being treated may be originally comminuted by any suitable device such as grinder or bowl chopper. Regardless of the manner in which the original material is comminuted, the size of the individual pieces in the original comminuted meat product may preferably have a maximum dimension of between two (2) inches and three-eighths (xe2x85x9c) of an inch.
The step of further comminuting the meat product after exposure to ammonia is preferably performed with a grinder, but may be performed with any suitable comminuting device such as a bowl chopper, for example. The maximum dimension of the individual pieces in the further comminuted meat product may preferably be no greater than three-sixteenths ({fraction (3/16)}) of an inch.
The step of exposing the comminuted meat product to ammonia may be performed with any suitable ammonia contacting device or arrangement. For example, a pump-type device such as that shown in U.S. Pat. No. 5,871,795 may be used to perform the ammonia exposing step according to the invention. In this pump-type device, ammonia gas is injected or otherwise directed into the pump cylinder along with meat products to be treated. The ammonia is then compressed and pumped together with the meat into a conduit which carries the ammoniated meat products to further processing equipment.
In the preferred form of the invention, however, the ammonia contacting arrangement includes an elongated contacting conduit having a chamber mounted in its interior. The chamber includes a number of openings which extend from an interior area of the chamber to the interior of the contacting conduit. Also, the chamber includes an ammonia supply tube which supplies ammonia to the interior area of the chamber. The annular area between the chamber and the inner wall of the contacting conduit preferably has a dimension no greater than the maximum dimension of the pieces of original comminuted meat being treated. In one preferred form of the invention, the distance between the inner wall of the contacting conduit and the outer surface of the chamber is between one-half (xc2xd) of an inch and one-eighth (xe2x85x9) of an inch.
These and other objects, advantages, and features of the invention will be apparent from the following description of the preferred embodiments, considered along with the accompanying drawings.